Which device is used to measure electrical current in a circuit?

• A. Voltmeter
• B. Ammeter
• C. Ohmmeter
• D. Wattmeter

Answer: (B)

The device specifically designed to measure electrical current in a circuit is an ammeter. This instrument is connected in series with the circuit under test, which allows it to measure the flow of electric charge. The measurement is typically displayed in amperes (A), the standard unit for electric current.

Understanding how an ammeter functions is crucial for electrical work, as it helps technicians and electricians assess the amount of current flowing through a circuit, which is vital for determining if everything is operating within safe and expected parameters. By monitoring current levels, one can identify potential issues such as overloads or inefficiencies that may require remedial action.

The other devices listed serve different purposes: a voltmeter measures voltage across two points in a circuit, an ohmmeter measures resistance, and a wattmeter measures power. Each of these tools plays an important role in diagnosing and troubleshooting electrical systems, but only the ammeter is dedicated to current measurement.